This invention relates to the improved design of waste water pump station pumping systems for the purpose of more efficient utilization and conservation of energy resources. The invention applies to two pump, waste water pump stations as well as pump stations having three or more pumps.
The conventional waste water pump station design employs two or more pumps. In two pump waste water pump station systems, one pump must be large enough to handle the in flow at any given time. The second pump is the stand bye, backup pump. It will turn on if the first pump fails. It also will turn on if, for some reason, the in flow rate exceeds the maximum capacity of the first pump under emergency conditions. The design is very inefficient and maintenance intensive. First off, the primary pump turns on and off each time the volume of fluid in the well reaches maximum and minimum levels respectively. The energy required to turn on a pump is significantly higher than that of a pump running at it's most efficient rate. Also, each time a pump turns off, kinetic energy is lost.
Regarding maintenance costs and useful life, a pump's useful life as provided by manufacturers' specifications, is based on the number of start-stop cycles. A typical life cycle for a pump under this design is approximately 7 years. In addition, maintenance requirements for pumps operating under this design are increased since stagnated waste water accumulating around an idle pump impeller enables debris to enter the immobilized impeller due to loss of the excessive resistant torque of a running pump.
A practical example to readers of all understanding of the energy efficiency and maintenance cost savings that can occur from this invention can be related to the process of an automobile that travels in rush hour traffic verse an automobile that travels at 3 am. Traveling during rush hour, with traffic constantly slowing down (comparative to modern pumps that use variable frequency drives) or stopping and going (comparative to older, less expensive, traditional pumps) results in miles per gallon loss compared to traffic running at the most efficient engine speed of an automobile (driving steadily at 45 mph on average). Also the wear and tear of stopping and going causes more maintenance to an automobile's parts than does that occurring from driving at a constant energy efficient speed. In addition, determining each engine's peak performance speed relating to steady mph provides valuable information as to the highest green performance operating speed.
That is exactly what the inventor does herein. The invention provides calculations required to determine the most efficient horsepower engines to employ in any waste water pump station by use of given formulas and the methods for accumulating the data necessary to establish the components of the formula.